Grounding clip with wrap-around tabs

ABSTRACT

An electrical grounding clip for interconnecting an electrically conductive strap of an electrical receptacle or switch to an electrically conductive mounting box. The clip comprises a flat, U-shaped, electrically conductive member having wrap-around tabs at its extremities and at its center to engage a mounting strap and a screw to hold the mounting strap to the mounting box so as to ground the strap to the box.

C United States Patent 1 1 1111 3,885,847

Thibeault May 27, 1975 GROUNDING CLIP WITH WRAP-AROUND 3,663,919 5/1972 Jaconette 339 14 R TABS 3,713,071 1/1973 Poliak et al. 339 14 R 3,784,953 1/1974 Lingaraju 339/14 R Inventor: Ronald Thlbeault, Buena Park, 3,810,069 5/1974 Jaconette 339/14 R Calif. 3,835,438 9/1974 Longworth 339/14 R 73 A' :SlB'Idt'I., sslgnee a i 3;; "es, nc Primary ExaminerRoy D. Frazler Assistant Examiner-Robert A. Hafer [22] Filed: Mar. 27, 1974 Attorney, Agent, or Firm-Smythe & Moore [21] App]. No.: 455,419

[57] ABSTRACT [52] U S Cl 339/14 R An electrical grounding clip for interconnecting an [51] In. .Cl 0 3/06 electrically conductive Strap of an electrical recepta [58] Fieid 151/41 cle or switch to an electrically conductive mounting 24/81 CC box. The clip comprises a flat, U-shaped, electrically conductive member having wrap-around tabs at its ex- [56] References Ched tremities and at its center to engage a mounting strap and a screw to hold the mounting strap to the mount- UNITED STATES PATENTS ing box so as to ground the strap to the box. 2,382,942 8/1945 Murphy 151/4175 3,575,371 4/1971 Carlstedt 24 129 B 5 Clams, 7 Drawmg Flgllres GROUNDING CLIP-WITH WRAP-AROUNDTABS This invention relates toagrounding device for'an electrical wiring device. More specifically, it relates to a grounding clip which mounts on the mounting strap of an electrical wiring device to contact an electrically conductive mounting box when the electrical wiring device is mounted in the mounting box by screws.

In order to avoid an electrically caused fire or to avoid injury to the user of anelectrical device connected to electricity, it is necessary to secure any exposed electrically conductive, non-current carrying portions of such devices to ground in a manner that provides positive, low resistance connections.

To electrically secure each electrical circuit to ground, each electrical receptacle or switch must be connected to an electrically conductive mounting box for proper grounding. This is achieved in the prior art in one manner by fastening a short length of insulated wire of a suitable size from a'terminal in the mounting box to a ground screw terminal on the electrical receptacle or switch. Such a procedureis time consuming and requires additional wiring, and difficulty is encountered in pushing the receptacle or switch into the mounting box. Furthermore, the electrician may be careless and omit the grounding wires. Another example of a grounding device is shown in US. Pat. No. 3,432,793.

One of the objects of the invention is to overcome the difficulties of prior grounding techniques.

Another of the objects of the invention is to provide a reliable means of obtaining a grounding path from the mounting strap of a switch or receptacle to a mounting box.

A still further object of the invention is to provide a grounding clip which will facilitate assembly of the various parts.

The grounding clip of the present invention comprises a flat, U-shaped, electrically conductive member having wrap-around tabs at the extremities and also in the center of the U-shaped member. The wrap-around tabs are resiliently biased to snugly engage a section of the mounting strap of an electrical receptacle or switch. The center wrap-around tab fits through a screw receiving slot in the mounting strap and the extremity wrap-around tabs fit over the end of the mounting strap if the strap is of such a type. A mounting screw is inserted into the screw slot with the clip engaged with the mounting strap so that as the screw is screwed into the mounting box, it will crush or engage the center wrap-around tab of the clip to insure good electrical contact between the mounting strap, screw and mounting box. Means can be provided to assemble the parts in a facile'manner.

These and other objects, advantages and features of the invention will become apparent from the following description and drawings, which are merely exemplary.

In the drawings:

FIG. 1 is a perspective view of a grounding clip according to the present invention;

FIG. 2 is a perspective view of the grounding clip of FIG. 1 on a mounting strap of an electrical receptacle;

FIG. 3 is a fragmentary sectional view of the grounding clip looking in the direction of line 3-3 of FIG. 2;

FIG. 4 is a sectional view similar to FIG. 3 with the fastening screw tightened; and

FIGS. 5, 6 and 7 are schematic views showing successive positions of one manner in which the parts can be assembled.

Where appropriate, the same reference numerals are used in the various figures to identify the same or similar parts.

Referring now to FIG. 1, a flat, U-shaped, electrically conductive member 11 has wrap-around tabs 12 and 13 at the extremities thereof. Another wrap-around tab 14 is in the center and inside of the U-shaped member 11. The clip is made of a suitable metal so that the wraparound tabs l2, 13 and 14 will be resiliently biased to snugly hold a thin sheet member therein.

With reference to FIG. 2, the electrically conductive clip 11 is shown mounted on an electrically conductive mounting strap 15 of an electrical receptacle 16. In this instance, a grounding plug type receptacle is shown but other electrical devices can be used. Tabs 17 and 18 at the extremities of the U-shaped member 1 1 'snugly hold the end of mounting strap 15 and can seat into a groove 19 formed adjacent an end of mounting strap 15 to further assist in holding the clip in place. The center tab 20 of the clip is located in a screw slot or aperture 21 of mounting strap 15. Mounting screw 22 passes through screw slot 21 in mounting strap 15. There is a friction engagement of screw 21 with center tab 20. The aforementioned friction engagement prevents screw 22 from falling free from mounting strap 15 and makes it unnecessary to use cardboard retainers as is currently common practice. The screw 22 threadedly engages the ears 23 of electrically conductive mounting box 24.

With reference to FIG. 3, a sectional view of FIG. 2 is shown with screw 22 shown in contact with the center tab 20 and threadedly engaged with mounting box 24. It should be clear from this view that the clip 11 has three points of contact with the mounting strap 16, i.e., tabs 17, 18 and 20.

With reference to FIG. 4, mounting strap 15 and clip 11 are shown tightly pulled against mounting box 24. The head of screw 22 is contacting and crushing tab 20 of clip 11 so that good electrical contact is made between screw 22 and clip 11. Thus, there is a low resistance contact from mounting flange 23, through the head of the screw 22, to the mounting box 24; from the mounting flange 23, through clip 11, through the head of the screw 22, to the mounting box 24; and from mounting strap 15, through clip 11, to the mounting box 24.

The grounding clip can be used on the type of receptacle shown having wings 26, 27 or can be used in types not having wings but only having a central screw slot.

The grounding clip may be easily installed on the mounting strap of the receptacle or switch by an automatic machine in large volume production.

Referring now to FIG. 5, electrical device 18 has been assembled to mounting strap 16. Clips 11 are controllably fed down incline 26 to stop 27. Stop 27 is retracted as seen in FIG. 6, and clip 11 will slide to a position under strap 16. Lift block 28 is then raised to the position shown in FIG. 7 so that tab 20 will move up through screw slot 21, the parts being so positioned as to permit this action. The outer tabs are to the outside of the strap 15. Retracted push arm 29 then will move to the left to the position shown in FIG. 7 so as to push the tabs into engagement with the mounting strap. The

3 push arm 28 then can be retracted to its starting posi tion of FIG. 5.

The size, shape and configuration of the grounding clip are capable of many variations for use with different sizes and types of electrical wiring devices.

It should be understood that various details of construction and arrangement of parts may be made without departing from the spirit of the invention except as defined in the appended claims.

What is claimed is:

1. An electrical clip grounding device for interconnecting an electrically conductive mounting strap of an electrical wiring device to an electrically conductive mounting box threadedly engageable by a mounting screw, said clip device comprising a flat, U-shaped, electrically conductive member having spaced legs bridged at the base thereof, wrap-around tabs at the free ends of said legs and on the bridge between the base of said legs of said U-shaped member, said wrap around tabs extending out of the plane of said flat U- shaped member, one edge of each tab being integral with said member while the opposite free edge extends towards said bridge, said wrap-aroundtabs being resiliently biased to snugly hold the mounting strap between said tabs and said U-shaped member.

2. An electrical clip grounding device as claimed in claim 1 wherein said base tab is mounted on the inside of said U-shaped member.

3. An electrical clip grounding device as claimed in claim 2 wherein said base tab is located on said U- shaped member such that said base tab can be locatable in a screw receiving slot in the mounting strap and said tabs at the extremities of said U-shaped member can engage one end of the mounting strap.

4. An electrical clip grounding device as claimed in ciaim 3 wherein said base tab located in said screw receiving slot of the mounting strap, a screw member is insertable for threadedly engaging the mounting strap to the mounting box, whereby the clip device makes low resistance electrical contact between the mounting strap, said screw and the mounting box.

5. An electrical clip grounding device as claimed in claim 3 wherein said tabs at the extremities of said U- shaped member will be able to engage a groove on one side of the mounting strap whereby said groove will assist in prevention of the U-shaped member from sliding off the mounting strap. 

1. An electrical clip grounding device for interconnecting an electrically conductive mounting strap of an electrical wiring device to an electrically conductive mounting box threadedly engageable by a mounting screw, said clip device comprising a flat, U-shaped, electrically conductive member having spaced legs bridged at the base thereof, wrap-around tabs at the free ends of said legs and on the bridge between the base of said legs of said U-shaped member, said wrap around tabs extending out of the plane of said flat U-shaped member, one edge of each tab being integral with said member while the opposite free edge extends towards said bridge, said wrap-aroundtabs being resiliently biased to snugly hold the mounting strap between said tabs and said Ushaped member.
 2. An electrical clip grounding device as claimed in claim 1 wherein said base tab is mounted on the inside of said U-shaped member.
 3. An electrical clip grounding device as claimed in claim 2 wherein said base tab is located on said U-shaped member such that said base tab can be locatable in a screw receiving slot in the mounting strap and said tabs at the extremities of said U-shaped member can engage one end of the mounting strap.
 4. An electrical clip grounding device as claimed in claim 3 wherein said base tab located in said screw receiving slot of the mounting strap, a screw member is insertable for threadedly engaging the mounting strap to the mounting box, whereby the clip device makes low resistance electrical contact between the mounting strap, said screw and the mounting box.
 5. An electrical clip grounding device as claimed in claim 3 wherein said tabs at the extremities of said U-shaped member will be able to engage a groove on one side of the mounting strap whereby said groove will assist in prevention of the U-shaped member from sliding off the mounting strap. 